Ribavirin capsules 200mg №60

Ribavirin-SZ

Ribavirin

1-β-D-ribofuranosyl-1H-1,2,4-triazole-3-carboxamide

Dosage form

capsules.

active ingredient: ribavirin - 200 mg.

lactose (milk sugar), colloidal silicon dioxide (aerosil), Magnesium stearate. Hard gelatin capsules No 0: gelatin; purified water;

dye: titanium dioxide.

White capsules No 0. The contents of the capsules are white or white powder.

yellowish tint color. Pharmacotherapeutic group: antiviral agent.

Pharmacology

Ribavirin is a synthetic nucleoside analogue with a pronounced antiviral

action. It has a wide spectrum of activity against various DNA and RNA viruses.

Pharmacodynamics.

Ribavirin readily penetrates infected cells and is rapidly phosphorylated by intracellular adenosine kinase into ribavirin mono-, di- and triphosphate.

These metabolites, especially ribavirin triphosphate, have pronounced antiviral activity. The mechanism of action of ribavirin is not clear enough. However, ribavirin is known to inhibit inosine monophosphate dehydrogenase (IMP),This effect leads to a pronounced decrease in the level of intracellular guanosine triphosphate (GTP), which, in turn, is accompanied by the suppression of the synthesis of viral RNA and virus-specific proteins. Ribavirin inhibits the replication of new virions, which reduces

viral load. Ribavirin selectively inhibits the synthesis of viral RNA without inhibiting the synthesis of RNA in normally functioning cells. Ribavirin is effective against many DNA and RNA viruses. The viruses that are most sensitive to ribavirin DNA are: Simplex herpes virus, poks-virus, virus of Marek illness s illness. Insensitive to ribavirin DNA viruses are: Varicella Zoster, pseudorabies, cow smallpox. The most sensitive to ribavirin RNA viruses are: influenza A, B, paramyxovirus (parainfluenza, epidemic parоtite, Nucasl illness s illness), reoviruses, RNA tumoral viruses. Insensitive to ribavirin RNA viruses are: enteroviruses, rhinovirus, Semlicy Forest. Ribavirin has activity against the hepatitis C virus (HCV). The mechanism of action of ribavirin against HCV is not fully understood. It is assumed that the accumulation of ribavirin triphosphate as phosphorylation proceeds to competitively inhibits the formation of guanosine triphosphate, thereby reducing the synthesis of viral RNA. Believed also

that the mechanism of the synergistic effect of ribavirin and Interferon alpha against HCV is due to increased ribavirin phosphorylation by interferon.

Pharmacokinetics.

- Absorption: for oral administration, ribavirin is rapidly absorbed in the gastrointestinal tract.

Moreover, its bioavailability is more than 45%. Distribution:

Ribavirin is distributed in the plasma, secretion of the mucous membrane of the respiratory tract and red blood cells.

A large amount of ribavirin triphosphate accumulates in the erythrocytes, reaching a plateau by day 4 and persisting for several weeks after administration. The half-distribution period is 3.7 hours. The volume of distribution (Vd) is 647 - 802 l. In exchange, ribavirin accumulates in plasma in large quantities. The ratio of bioavailability (AUC is the area under the curve "concentration / time") with repeated and single dose is 6. A significant concentration of ribavirin (more than 67%) can be detected in the cerebrospinal fluid after prolonged use. Slightly binds to plasma proteins. The time to reach maximum plasma concentration is from 1 to 1.5 hours. The time to achieve therapeutic plasma concentration depends on the magnitude of the minute volume of blood. The average maximum concentration (Cmax) in plasma: about 5 μmol per liter at the end of 1 week of administration at a dose of 200 mg every 8 hours and about 11 μmol per liter at the end of 1

week of admission in a dose of 400 mg every 8 hours.

- Biotransformation: ribavirin is phosphorylated in liver cells into active metabolites in the form of mono-, di-, and triphosphate, which are then metabolized to 1,2,4-triazolecarboxamide (amide hydrolysis to tricarboxylic acid and de-ribozylation to form a triazole carboxylic metabolite).

- Excretion: Ribavirin is slowly eliminated from the body. The half-life (T1 / 2) after a single dose of 200 mg is from 1 to 2 hours from plasma and up to 40 days from red blood cells.After cessation of the course intake, T1 / 2 is about 300 hours. Ribavirin and its metabolites are mainly excreted by the kidneys. Only about 10% is excreted through the intestines. In unchanged form, about 7% of ribavirin is eliminated in 24 hours and about 10% in 48 hours. Pharmacokinetics in special clinical conditions: When taking the drug in patients with renal insufficiency, the AUC and Cmax of ribavirin increase, which is due to a decrease in the true clearance. In patients with hepatic insufficiency (A, B and C degrees), ribavirin pharmacokinetics do not change. After taking a single dose with food containing fats, ribavirin pharmacokinetics changes significantly (AUC and Cmax increase by 70%).

Indications and usage

Chronic hepatitis C (in combination with interferon alfa-2b or peginterferon alfa-2b): in primary patients who have not previously been treated with interferon alfa-2b or peginterferon alpha-2b; during exacerbation after a course of monotherapy with interferon alfa-2b or peginterferon alfa-2b; in patients immune to monotherapy with interferon alfa-2b or peginterferon alfa-2b.

Contraindications

Hypersensitivity, pregnancy, lactation, chronic heart

major IIb-III failure, myocardial infarction, renal failure (creatinine clearance less than 50 ml / min), severe anemia, liver failure, decompensated liver cirrhosis, autoimmune diseases (including autoimmune hepatitis), non-treatable thyroid disease glands,

severe depression with suicidal intent, childhood and adolescence (up to 18 years).

Carefully.

Women of reproductive age (pregnancy is undesirable), decompensated diabetes mellitus (with bouts of ketoacidosis);

chronic obstructive pulmonary disease, pulmonary thromboembolism, chronic heart failure, thyroid disease (including thyrotoxicosis), bleeding disorders, thrombophlebitis, myelodepression, hemoglobinopathy (including thalassemia, sickle cell anemia), depression, hemoglobinopathy suicidal tendency (including history), old age.

Dosage and Administration

The drug should be taken orally, without chewing and drinking water, together with food intake of 0.8 -1.2 g per day in 2 divided doses (in the morning and in the evening). At the same time, interferon alfa-2b is prescribed subcutaneously, in doses of 3 million IU 3 times a week or peginterferon alpha 2b subcutaneously, 1.5 mcg / kg 1 time per week. When combined with interferon alpha-2b with body weight up to 75 kg, the dose of ribavirin is 1 g per day (0.4 g in the morning and 0.6 g in the evening); above 75 kg - 1.2 g in

day (0.6 g in the morning and 0.6 g in the evening). When combined with peginterferon alpha-2b with a body weight less than 65 kg, the dose of ribavirin is 0.8 g per day (0.4 g in the morning and 0.4 g in the evening); 65 - 85 kg -1 g per day (0.4 g in the morning and 0.6 g in the evening); more than 85 kg (0.6 g in the morning and 0.6 g in the evening). The duration of treatment is 24 to 48 weeks; at the same time for previously untreated patients - at least 24 weeks, in patients with the genotype 1 virus - 48 weeks. In patients who are not susceptible to monotherapy with interferon alpha, as well as during relapse - at least 6 months to 1 year (depending on the clinical course of the disease and the response to the therapy being carried out).

- For the nervous system: headache, dizziness, general weakness,

malaise, insomnia, asthenia, depression, irritability, anxiety,

emotional lability, nervousness, agitation, aggressive behavior, confusion; rarely - suicidal tendency, smooth muscle tone, tremor, paresthesia, hyperesthesia, hypoesthesia, syncope.

- On the side of the cardiovascular system: a decrease or increase in blood pressure, brady- or tachycardia, palpitations, cardiac arrest.

- From the side of blood-forming organs: hemolytic anemia, leukopenia, neutro

singing, granulocytopenia, thrombocytopenia; extremely rarely - aplastic anemia.

- On the part of the respiratory system: dyspnea, cough, pharyngitis, shortness of breath, bronchitis, otitis media, sinusitis, rhinitis.

- For the digestive system: dry mouth, decreased appetite, nausea,

vomiting, diarrhea, abdominal pain, constipation, taste perversion, pancreatitis, flatulence, stomatitis, glossitis, gingival bleeding, hyperbilirubinemia.

- For the senses: damage to the lacrimal gland, conjunctivitis, blurred vision, impairment / loss of hearing, tinnitus.

- For the musculoskeletal system: arthralgia, myalgia.

- On the part of the urogenital system: hot flashes, decreased libido, dysmenorrhea, amenorrhea, menorrhagia, prostatitis.

- Allergic reactions: skin rash, erythema, urticaria, hype

rtermia, angioedema, bronchospasm, anaphylaxis, photosensitivity, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis.

- Others: hair loss, conjunctivitis, alopecia, impaired hair structure, dry skin, hypothyroidism, chest pain, thirst, fungal infection, viral infection, flu-like cider, sweating, lymphadenopathy.

Perhaps increased severity of side effects. Treatment: drug withdrawal, symptomatic therapy.

Interaction with other drugs.

Drugs containing compounds of magnesium and aluminum, simethicone reduce the bioavailability of the drug (AUC is reduced by 14%, has no clinical significance).

When combined with interferon alpha-2b or peginterferon alpha-2b-synergism action. The administration of ribavirin during treatment with zidovudine and / or stavudine is accompanied by a decrease in their phosphorylation, which can lead to HIV viremia and require changes in the treatment regimen. Increases the concentration of phosphorylated metabolites of purine nucleosides (including didanosine, abacavir) and the associated risk of developing lactic acidosis. Does not affect the enzymatic activity of the liver with the participation of cytochrome P450. Simultaneous high-fat meals increase the bioavailability of ribavirin (AUC and Cmax increase by 70%).

Consider the teratogenicity of the drug, men and women of reproductive age during treatment and within 7 months after the end of therapy should use effective contraceptives.Laboratory

Studies (blood count with counting of leukocyte formula and platelet count, determination of electrolytes, creatinine content, liver function tests) should be carried out before the start of therapy, at 2 and 4 weeks, and then regularly. In the process of treatment with ribavirin, the maximum decrease in hemoglobin content in most cases is observed after 4-8 weeks from the start of treatment. With a decrease in hemoglobin below 110 mg / ml, the dose of ribavirin should be temporarily reduced by 400 mg per day; with a decrease in hemoglobin below 100 mg / ml, the dose should be reduced to 50% of the initial dose. In most cases, the recommended dose changes ensure recovery of hemoglobin levels. With a decrease in hemoglobin below 85 mg / ml, the drug should be discontinued. In acute manifestations of hypersensitivity (urticaria, angioedema, bronchospasm, anaphylaxis), the use of the drug should be immediately stopped. Transient rash does not warrant interruption of treatment. During the period of treatment, persons experiencing fatigue, drowsiness or disorientation should refrain from driving vehicles and activities.

potentially hazardous activities that require increased concentration of attention and quickness of psychomotor reactions. In connection with the possible deterioration of renal function in elderly patients, before using the drug, it is necessary to determine renal function, in particular, creatinine clearance.

List B.In a dry, dark place, at a temperature not higher than 25 ° C. Keep out of the reach of children.